Chaeles b



2 Sheets-Sheet 1.

(No Model.)

0. B.-BOYNTON.

HOT AIR FURNACE.

Patented Dec. 11

N. Prrini mmo-umm bm. Wluhinltm. \Lc.

2 Sheets-Sheet. 2.

' (No Model.)

'G. B. BOYNTON. HOT AIBFU-RNAGE.

No. Z89, 967.

Pajzented Dec. 11; 1883. v

ATTORNEYS.

N. PETERS MUM-mm Nahum D.C.

' UNr-rnn; STATES PATENT OFFICE".

CHARLES B. BoYnTon, on NEW YORK, N. Y.

HOTfAlR IFURNAILCE.

. SPECIFICATION forming part OfLettersPatent No. 289,96'7, dated December 11, 1883.

Application filed September 12 188 2. (X model.)

- drawings, forming part of this specification,

'in which similar letters of reference indicate corresponding parts in all the figures.

Figure 1 is a broken perspective view-of my improved hot-air furnace. Fig. 2 is an inverted plan view of the radiator. j Fig. 3 is a sectional elevation of the radiator, taken on the line m 00 of Fig. 2. Fig. 4. is a plan view of the annular bottom or supporting plate of the radiator; and Fig. 5 is a sectional ele-v vation taken on the liney 1 of Fig. 4, showing the radiator and bottom plate thereof placed upon the dome of the furnace.

The first object of this invention is to promote economy in the consumption of fuel in hot-air furnaces by retarding the products of combustion in their passage to the chimney until all of the available heat is extracted therefrom by the ascending air. This object I accomplish by means tion and combinations of pa s, substantially as hereinafter fully set forth and claimed.

Referring to the drawings, A represents the sheet-metal casing of the furnace, which is of ordinary construction, and B represents the corrugated east-iron fire-pot, and O the corrugated cast-iron dome, which is contracted at its upper end, as shown at c, Fig. 5, for receiving the annular cast-iron top or' supporting plate, D, and radiator E, as clearly illustrated in said figure and in Fig. 1. r

I The radiator E is by preference made of cast-iron, but may be made, of sheet-iron or of both cast and sheet iron, and is made hollow, and by preference is in general form that of an annulus, but with the inwardly-projecting radial extension E,which extension is rounded, and is adapted to fit upon or inand to form a good joint with the upper reduced end of the dome O, as shown clearly in Fig. The passages F F in the interior of the'hollow radiator E and the extension Ethercof aret-he passages through which theproducts of combustion pass from the fire-pot to the chimneyopening H, and the space J, between the outer f the construc-' surface or the inner wall, f, of the radiator and theouter surface of the wall f of the extension E, is the air-heating space of the radiator, which spaceis made larger 'at the top than at the bottom by making the said walls ff slightly diverging away from each other from the bottom toward the top, and this diverging of the walls f f at the same time contracts the size of the smoke and flame flues or passages F F from the bottom toward the top, as shown. V

The chimney-opening H is formed, in the outer wall of the radiator, a little to one side of the confluence of the passages F F, as shown in Fig. 2, and in the passage F, between the line of the passage F and the chimney-opening H, is placed the partitionK, thus causing the products of combustion issuing 'from'the fire-pot to traverse the entire circuit of the interior of the radiator, as indicated by the arrows in Fig. 2, before reaching the chimney-passage. Y

The bottom plate, D, of the radiator has the inwardly-projecting extension D, which is curved at its end and formed with the lip d, which is adapted to fit in and form a good joint with the upper edge of the dome O, as shown in Fig. 5, and upon the upper surface of this plate are formed the double sets of flanges d d, between which the tongues b b, formed on the lower edges of the radiator E, areadapted to fit, as shown'iu Fig. 5, for forming a perfectly gas-tight joint between the radiator and-plate, these parts being adapted to be bolted together bybol ts passing through the corresponding lugs, t i, formed, respectively, upon the radiator and the plate.

h h are braces extending from the walls j" of the extension E of the radiator to the wall f thereof, at their lower edges, for strengthening and rendering the radiator firm and rigid, and N is a covered opening in the outer; wall of the radiator, through which the radi ator may be cleaned- Constructed in this manner, the air entering the casing A will be come heated from contact witl the body B C of the furnace and exterior of the radiator E, in the ordinary way, and a portion of the air will ascend through the central opening, M. of the plate D, into the heating-space J, and become still further heated from contact with the interior walls of the radiator. 'Thisheating-space, being larger at the top than at the bottom, accommodates the increase in volume of the air, due to its expansion from the additional heat which it takes up, and thus does not in any manner retard or restrain the upward current of the heated air, but, on the contrary, facilitates and increases it; and the products of combustion from the burning fuel in the furnace, being compelled to traverse the whole circuit of the spaces F F of the radiator, are retarded in their course to the chimney and longer exposed to the air to be heated, and they heat a greater exposed surface of the radiator than they otherwise would, so that the maximum amount of heat from the fuel will be utilized, thus greatly i11- creasing the efticiency and heating-power of the furnace with a less consumption of fuel. Besides these advantages, the flanges cl (1 of the plate D and the tongues b b of the radiator, and the method of placing the plate and radiator upon the reduced opening 0 of the dome C, so that all points are about on a level with the top of the dome and below the ehimney-opening H, render the furnace perfectly gas-tight, as the easiest escape for the gas will be through the chimney-opening H, it being nearer to the top of the radiator, where the gas will collect, than any joint in the furnace. Furthermore, the tines or passages F F being smaller at the top than at the bottom, the smoke, gases, flame, &c., are caused to expand in a chamber gradually diminishing in size upward, and are thus most limited and confined in their expansion at the top of the chamber, which causes the products of combustion, in their course to the chimneyopening, to hug the lower part of the tines or spaces F F. thus facilitating andvincreasing the draft of the furnace, while at the same time a considerable amount of heat is retained or retarded at the top of the radiator.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a hot-air furnace, the dome-like radiator consisting of the annular chamber E, the central chamber, E, and passage F, connecting the said chambers together, the sides of the said chambers and passages being contracted toward and at the top, whereby the air-space between the same is widened at the upper end, substantially as and for the purpose set forth.

2. In a hot-air fu1-nace,the combination,with

the annular chamber E, central chamber, E,

and passage F, of the common bot-tom plate, D D, with the grooved flanges d d, extcnding around its edges, and adapted to receive the tongues b of the sides ofthe annular chamber and passage, gas-tight, substantially as and for the purpose set forth.

CHARLES l3. BOYNTON. \Vitncsses:

H. A. XVEs'r, SEDGwIcK. 

